PHYSICAL AND LITERARY. 309 
mufcles produced any contraction in them, 
or any motion in the members to which 
they belonged. After cutting off its head, 
a probe pufhed into the fpinal marrow 
made its fore-legs contract feebly. 
3. EIGHTEEN minutes paft four in the 
afternoon, I injected a ftronger turbid 
folution of opium in water than that ufed 
in the preceeding experiments *, into the 
ftomach and guts of a frog; and, as it 
{quirted out moft of the folution injeted 
by the anus, I threw in fome more in its 
place. At twenty four minutes patt five, 
I opened this frog, and obferved the-heart 
with its auricle greatly diftended with 
blood and beating very flowly, not above 
feven timesinaminute. When the heart 
was touched with the point of a pair of 
{ciflars, its motion was rendered quicker 
for two or three pulfations: After which it 
became as flow as before. 
4. IMME- 
* Viz, half an ounce of opium diffolved in eight oun- 
ces of water; which was alfo made vfe of in all the fol-- 
lowing experiments. The heat of the folution was near- 
ly the fame in all the experiments, viz. about 60 degrees 
of Farenheit’s thermometer. 
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